813752381 has 4 divisors (see below), whose sum is σ = 876348732. Its totient is φ = 751156032.

The previous prime is 813752363. The next prime is 813752393. The reversal of 813752381 is 183257318.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 59151481 + 754600900 = 7691^2 + 27470^2 .

It is a cyclic number.

It is not a de Polignac number, because 813752381 - 2¹⁴ = 813735997 is a prime.

It is a super-2 number, since 2×813752381² = 1324385875166338322, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (813752321) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 31298156 + ... + 31298181.

It is an arithmetic number, because the mean of its divisors is an integer number (219087183).

Almost surely, 2^813752381 is an apocalyptic number.

It is an amenable number.

813752381 is a deficient number, since it is larger than the sum of its proper divisors (62596351).

813752381 is a wasteful number, since it uses less digits than its factorization.

813752381 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 62596350.

The product of its digits is 40320, while the sum is 38.

The square root of 813752381 is about 28526.3453845739. The cubic root of 813752381 is about 933.6069816505.

The spelling of 813752381 in words is "eight hundred thirteen million, seven hundred fifty-two thousand, three hundred eighty-one".